| 摘要: |
| 根据三峡水库一期蓄水3 a 后(2006 年)长江口海域表层沉积物样品中元素(Cd, Cr, Cu, Pb, Zn, Al,As, Ca 和Sr 等)质量比和黏土组分百分含量, 采用Hakanson 潜在生态风险指数法, 分析了长江口海域表层沉积物中重金属元素(Cd, Cr, Cu, Pb, Zn 和As)的污染程度, 评价了长江口海域表层沉积物的环境质量现状, 定量分析了长江口海域表层沉积物的潜在生态风险程度, 并结合2003 年的资料, 讨论了三峡水库一期蓄水3 a 后长江口海域的环境变化。结果表明, 长江口海域表层沉积物环境质量状况良好, 6种重金属元素的污染程度排序为: As＞Cr＞Cd＞Zn＞Cu＞Pb; 表层沉积物的潜在生态风险程度为“轻度”, 6 种重金属元素的潜在生态风险程度排序为: Cd＞As＞Cu＞Cr＞Pb>Zn。从区域差异来看, 杭州湾口外泥质区和长江口外东北偏北海域表层沉积物中重金属元素(As, Cr, Zn, Cu 和Pb)的污染指数和潜在生态风险指数均出现相对高值。从元素差异来看, Cd 的污染指数和潜在生态风险指数高值区的分布明显异于其他重金属元素, 说明Cd 存在与其他重金属元素不同的富集机制, 很可能是因为Cd 更易受悬浮体浓度、有机质含量以及水体盐度的影响。与2003 年的资料相比, 三峡水库一期蓄水3 a 后(2006年)表层沉积物总体潜在生态风险程度和重金属元素(除Cd 之外)潜在生态风险指数的高值区均未发生显著变化。
|
| 关键词: 沉积物 长江口 重金属元素 潜在生态风险评价 |
| DOI： |
| 分类号: |
| 基金项目:国家973 项目(2002CB412409) |
|
| Evaluation on potential ecological risk of the heavy metals in the surface sediments of the Changjiang (Yangtze) estuary and its adjacent coastal area |
|
DONG Ai-guo,ZHAI Shi-kui,YU Zeng-hui,HAN Dong-mei
|
| Abstract: |
| Based on the contents of elements (Cd, Cr, Cu, Pb, Zn, Al, As, Ca, Sr, ect) and clay in the surface sediments of Yangtze estuary and the surrounding area in 2006, using Hakanson ecological risk index method, we analyzed the contamination degree of heavy metals in the surface sediment, evaluated the environmental quality status of surface sediments, and defied the potential ecological risk of surface sediments. We found that there was a good quality status in surface sediments of Yangtze estuary and its adjacent area, and the order of contamination content in sediments was As>Cr>Cd>Zn>Cu>Pb. In addition, the potential ecological risk of heavy metals was also “low”; and the order of potential ecological risk index was Cd>As> Cu> Cr> Pb> Zn. Geographically, the relative high value of contamination degree and potential ecological risk were seen in the mud area outside Hangzhou bay and southeast of Yangtze estuary. Among the heavy metals, Cd showed a value of contamination degree and potential ecological risk that were significantly higher than other elements, probably because Cd were more affected by the concentration of suspended particular matter, the content of organic matter and salinity than other elements. Compared with the data of 2003, the potential ecological risk of heavy metals and high value of potential ecological riskindex were not significant changed.
|
| Key words: sediment the Changjiang (Yangtze) estuary heavy metals potential ecological risk evaluation |
